Elevator door operating mechanism



May 5, 1953 J. H. BORDEN ELEVATOR DOOR OPERATING MECHANISM 3 Sheets-Sheet 1 Filed Oct. 27, 1948 INVENTOR. J03 e o/r h. flora er? b BY i QTT RNE YS May 5, 1953 J. H. BORDEN 2,637,549

ELEVATOR DOOR OPERATING MECHANISM Filed Oct. 27, 1948 5 Sheets-Sheet 2 INVENTOR. Jose 0h f7. Borden In w MW ATTORNEY May 5, 1953 J. H. BORDEN 2,637,549

ELEVATOR DOOR OPERATING MECHANISM Filed Oct. 27, 1948 3 Sheets-Sheet 3 IN V EN TOR.

T ORNEYS Patented May 5, 1953 ELEVATOR DOOR OPERATING MECHANISM Joseph H. Borden, Toledo, Ohio, assignor to Haughton Elevator Company, Toledo, Ohio, a

corporation of Ohio Application October 27, 1948, Serial No. 56,738

9 Claims.

This invention relates to elevator door operating mechanisms.

The cab of a modern elevator is equipped with sliding doors which remain closed while the elevator is in motion and which must be opened and then closed each time that the elevator stops at a floor. There are two general types of elevator cab doors: center-parting doors and overlapping doors. Center-parting doors are those which meet at the center of the opening in the elevator cab and open outwardly in opposite directions. Overlapping doors are those which are located at one side of the cab, usually closing and opening approximately two-thirds of the cab width, and which both open in the same direction, one of the doors moving in front of the other door. In a pair of overlapping doors one of the doors is called a high speed door and the other a "slow speed door" because that door farthest from the retracted position must move twice as far as the closer door during the opening operation.

Because an elevator cab is not performing any useful work when it is stationary at a floor level during the time when the doors are either opening or closing, it is desirable that the length of time required to fully open or fully close the doors should be as short as possible so that the delay in the movement of the cab occasioned by the door operation is reduced as much as possible. It is desirable, therefore, that the operating mechanism which actually opens and closes the doors should operate at as high a speed as possible.

Each floor of a building also has a door which closes the elevator shaft to prevent entrance into the shaft except when the cab is in position level with the floor. The landing doors usually are of the same type as the elevator doors and usually are operated by the elevator doors with a clutch mechanism of some type (mounted on either the landing or elevator doors) so that when the elevator doors are moved, the landing doors are moved with them. For this reason an elevator door operating mechanism must be powerful so that the heavy load of both sets of doors can be rapidly moved during the opening and closing process. The total weight to be moved is quite substantial because the landing doors, in particular, must be strong for safety purposes. operating mechanism presents quite a problem inasmuch as it must pick u a dead load from a stationary position, quickly move the load to open the doors, and bring it to a quick, smooth stop; and then reverse the process.

For these reasons the elevator door It is the principal object of this invention to provide a high-speed elevator door operating mechanism which is designed for use with either center-parting or overlapping doors and which is powerful and rapid in operation.

It is a further object of this invention to provide a high-speed elevator door operating mechanism which is equipped with a constantly acting over-center device which tends to urge the doors toward either the fully open or fully closed position, which ever position is closer to the actual. position of the doors at the time.

It is yet another object of this invention to provide a high-speed elevator door operating 1 mechanism in which the movement of the doors is under the control of a fluid cylinder thus imparting to the movement of the doors a smooth easy movement accomplished by metering the fluid within the cylinder.

These and more specific advantages will be ap arent from the drawings, in which:

Figure I is a view in elevation (partly broken away) of an elevator cab equipped with overlapping doors actuated by a door operating mechanism embodying the invention.

Figure II is a greatly enlarged view in trimetric projection of an elevator door operating mechanism embodying the invention.

Figure III is a quarter-sectional view, with parts broken away, of a control cylinder used in a mechanism embodying the invention.

Figure IV is a diagrammatic view on a greatly reduced scale showing the operation of the overcenter mechanism illustrated in Figures I and II.

Figure V is a greatly enlarged detail view of fluid metering means employed in the cylinder shown in Figure III.

In Figure I there is shown an elevator cab, designated by the numeral I, which is shown as being equipped with a pair of overlapping doors 2 and 3. The doors 2 and 3 are, respectively, a slow-speed door and a high-speed door. The doors run on two tracks 4 which are spaced horizontally from each other. The high-speed door 3 passes in front of the low speed door 2 when the doors are open d, both of the doors bein moved to the left side of the cab as shown in Figure I when the doors are open. The door 2 is operatively connected to an actuating lever 5 by means of a link 6. The door 3 also is operatively connected to the actuating lever 5 by means of a similar link I.

The actuating lever 5 is pivotally mounted;

upon a pin 8 (see Figure II) which is, in turn; mounted upon a crossbar 9 forming part of.- a-

sub-frame generally designated Ill. The subframe I is secured to a pair of crossheads I I which are erected on vertical frame members |2 (Figure I) above the cab. The sub-frame |0 comprises a pair of downwardly extending angle brackets l3 and M which are bolted or otherwise secured to the forward one of the crossheads The angle bracket l3, at its upper end, is welded or otherwise secured to a substantially U-shaped frame |5 mounted in turn by an angle IE on the two crossheads A channel I! is welded between the arms of the U-shaped frame and extends across atop the crossheads H, the other end of the channel |1 being welded or otherwise secured to the upper end of the angle bracket l4. This structure is made very rigid and is firmly secured to the crossheads since it supports the actuating lever 5 and the motive mechanism therefor.

The upper end of the actuating lever 5 carries a yoke I8, at each end of which there is pivotally connected a fitting l9. Each of the fittings i9 is secured on the upper end of a plunger rod which extends downwardly into one of a pair of fluid cylinders 2|. The fluid cylinders 2| extend downwardly one on each side of the actuating lever 5 and approximately parallel thereto, their lower ends beingpivotally mounted in cars 22 which, in turn, are secured on the lower ends of the angle brackets I3 and M. The yoke H? has a substantially cylindrical upper surface, at the crest of which there is secured a grooved clamp 23. The clamp 23 connects the yoke l8, and thus the lever 5, to a pair of V-belts 24 which are engaged in a pair of spaced pulleys 25 and 26. The axes of the pulleys 25 and 26 are substantially parallel and are substantially perpendicular to the plane of movement of the actuating lever 5, i. e., their axes and the axis of the lever 5 being substantially parallel.

The pulley 25 is rotatably mounted upon a pin 21 which extends between the upper arms 28 of a pair of bell crank levers 29, in turn pivotally mounted on a block 30 secured to the upper end of the angle bracket M. The lower arms 3| of the bell crank levers 29 carry an adjustable connection 32 to which is attached the upper end of a coil spring 33, the lower end of the spring 33 being secured to an angle 34 mounted on the angle bracket I4.

The pulley 26 is rotatably mounted in a pair of spaced arms 35 (only one of which is shown in the drawing) which extend upwardly from the U frame l5. The pulley 26 is either integral with or secured to a larger pulley 36 in the grooves of which are engaged V-belts 31 also engaged in a motor pulley 38 which is mounted on the shaft of a reversible driving motor 39 secured in turn on a motor block 40 attached to the top of the channel H,

The doors of the elevator cab are opened or closed by energizing the reversible motor 39 to rotate in the proper direction. For example, if the doors are closed as shown in Figure I the motor 39 is energized to rotate in a counterclockwise direction. This, through the driving connection of the belts 31 and pulley 36 rotates the pulley 26 in a counterclockwise direction which pulls on the lower run of the belts 24 and, through the clamp 23, on the crosshead l8. This moves the crosshead I8 and thus the upper end of the actuating lever 5 to the right in Figure I and moves the lower end of the actuating lever 5 and the doors 2 and 3 to the left in Figure I. As can best be seen in Figure IV, because the lever 5 is pivoted on the fixed pin 8, the upper end of the lever 5 moves in an arcuate path and as it moves toward the center increases the tension on the belts 24 by forcing the lower run of the belts upwardly in the center. This center position is shown in Figure II and in broken lines in Figure IV. Because of the increased tension on the belts 24, the pulley 25 is bodily translated inwardly toward the pulley 25 pivoting with the bell crank lever 29 against the tension of the spring 33. This increase in tension of the spring 33 continues until the bell crank lever 5 passes the center position. The second half of its path of movement, i. e., from center to the right-hand position shown in the solid lines in Figure IV, decreases the tension on the belts 24 and the spring 33 retracts, moving the pulley 25 upwardly and to the left and urging the upper end of the bell crank lever 5 toward the right. The constantly increasing and then decreasing tension of the belts 24 which has just been described (as applied thereto by the coil spring 33) constitutes an over-center action tending to swing the actuating lever 5 to the limit of its travel in either direction, in particular, toward that end of its travel which is closer to the particular position of the actuating lever 5 at any time. Thus the elevator doors are urged by the coil spring 33 either toward their fully open position or toward their fully closed position, assuring that the doors will not remain half open in the event of any failure of other portions of the mechanism.

The mechanism so far described, although satisfactory as a high-speed door operating mechanism, provides for regulating the speed of opening and closing the doors only by means of control over the speed of the motor 39. Since this motor must have an extremely high torque in order to afford suflicient power to operate the doors and since it operates for only a relatively few rotations, it has been found advantageous to provide other speed controlling mechanism to determine the speed at which the doors are moved, not only during the majority of their movement but also and, more particularly, at the limits of their movement. Ihe elevator doors should start quite rapidly away from either the open or closed position, move quite rapidly'almost up to the other position and come to a slow smooth stop to prevent their slamming either open or closed. The speed of movement of the elevator doors is controlled by the two fluid cylinders 2|. Each of the fittings l9 (see Figure III) is securely connected on the upper end of a plunger rod 20 which extends downwardly into the cylinder 2| through a packing gland 4|. The plunger rod 20 is guided in its vertical movement by a bafi'le 42 which is mounted on the lower ends of a pair of rods 43 which are, in turn, screwed into a cap 44 which closes the upper end of the cylinder 2|. The lower end of the plunger rod 20 is secured, by means of a transverse pin 45, to a plunger 46. The plunger 46 snugly fits the interior of the cylinder 2| sliding back and forth in the cylinder 2| as the plunger rod is withdrawn and inserted by action of the yoke l8 rocking back and forth with the actuatin lever 5. The plunger 46 is provided with a passageway 41 for the passage of fluid, the passageway 41 being in communication with a horizontal passageway 48 leading to a centerbore 49. The passageway 41 is concentric with a slightly enlarged passageway 58 in which there is a ball check valve 5|. Concentric with the plunger rod 20 and the centerbore 49 is a small orifice 52 leading from the accused:

centerbore 49 to a socket shaped opening 53 bored in the underside of the plunger 46 and thus connecting the underside of the plunger 46 through the centerbore 49, passageway 48 and passageway 41 with the upper side of the plunger 46. Thus, when the plunger 45 is moved downwardly in the cylinder the fluid which is located beneath the plunger passes upwardly through the opening 53 and orifice 52 which meters the rate of flow, controlling the speed at which the plunger 36 can be moved downwardly through the cy1- inder 2|.

Downward movement of the plungers 46 takes place alternately in the two cylinders 2| as the actuating lever 5 is swung back and forth to open and then close the doors under control of that particular one of the cylinders 2| whose plunger is moving downwardly. As can be seen in. Figure II, for example, the right-hand one of the cylinders 2| controls the movement of the actuating bar in a clockwise direction and thus controls the movement of the doors while they are o ening. When the motor 39 is energized to rotate in a counterclockwise direction the actuating lever 5 is swung in a clockwise direction to open the doors moving the right-hand one of the plunger rods 20 and its plunger 46 downwardly into its cylinder 2|, the speed of movement and thus the speed of the doors being controlled by the metering orifice 52. v

A pin 54 (see also Figure V) is mounted in a hollow stud 55 in a wall forming the lower end of each of the cylinders 2|, the stud 55 and pin 54 being concentric with the cylinder 2| and the plunger 46. The pin 54 has a cylindrical center portion 56, a conically tapered portion 5i and its lowermost part is in the shape of a ball 55. A small coiled spring 59 is positioned in the interior of the hollow stud 55 urgingv upwardly against the ball shaped portion 58 of the pin 54. The pin 54 is thus in line with the orifice 52 in the plunger 46. Therefore, as the plunger 46 approaches the lower end of the cylinder 2| (and thus the doors approach their open position) the tapered portion of the pin 54 enters the orifice 52. This obstruction in the orifice 52 cuts down on the amount of fluid that can pass therethrough and thus quite quickly slows down the movement of the plunger 45 and of the doors. Because the portion 51 of the pin 54 is tapered, the deceleration is progressive with more and more of the tapered portion 5'! entering the orifice 52 and cutting down further and further on the amount of fluid which can flow therethrough until the pin completely fills the orifice 52 with its cylindrical portion 55, closing the orifice 52, preventing the passage of any more fluid therethrough, and stoping the doors. The spring 59 and ball shaped portion 58-.of the pin 54 permit a certain amount of play to take place to prevent damage in. event of a slight mismatch between the pin 54 and the orifice 52.

When it is desired to close the doors the motor is energized in reverse, 1. e., clockwise, the belts correspondingly moved and the actuating lever 5 swung in a counterclockwise direction. This moves the left one of the fittings i9 and its plunger rod 20 and the plunger 46 through the operations just described and, in contrast, withdraws the right-hand one of the plunger rods 20 lifting its plunger 46 upwardly in its cylinder 2|. When one of the plungers 46 is lifted upwardly the fluid which is above the plunger t6 passes downwardly through the passageway 4'! displacing the ball check valve 5| downwardly against the pressure of its spring and opening the en larged passageway 50 to allow the fluid to pass.

beneath the plunger 46. The passageways 41 and 50 are so much larger than the orifice 52 which is metering the downward movement of the controlling plunger at this time, that the upwardv movement of the inactive plunger exerts no force'- and has no effect on the operation of the mecha nism as a whole;

Thus, by virtue of the controlled movement or.

the movement similarly smoothly and effectively controlled.

Throughout the above description it is assumed that an elevator door actuating mechanism which comprises the mechanism mounted on the sub-frame l0 and actuating lever 5, can be connected with equal facility to doors of the overlapping type which are shown in the drawings or to doors of the center-parting type. The only differences in construction for doors of the cemter-parting type is in the links 6 and and in their connections to the doors. Since the con nections between the actuating lever 5' and the doors do not constitute a part of this invention, no drawings or description has been provided of the operation of center-parting doors except generally. The specific embodiment of the invention which has been described is merely illustrative of an organization of parts in which the efiective, controlled, high-speed elevator door operating mechanism of the invention is embodied.

Having described the invention, I claim:

1. Elevator door operating mechanism, comprising, in combination, an actuating lever pivoted on the elevator cab and operatively linked at one end to said door. a pair of spaced pulleys having substantially parallel axes and mounted on said cab one near each end of the path of the other end of said lever, one of said pulleys being mounted for translatory movement laterally of. the axis thereof, means urging said translatable pulley away from the other of said pulleys, a loop of flexible belting engaged in said pulleys, means for securing the other end of said lever to said belt between said pulleys, said other end. of said lever serving to deflect said belt from a direct linebetween said pulleys in an amount that decreases toward each end of the path of said lever where-- by said lever is urged toward the nearer end of its path of travel, and driving means for rotating one of said pulleys.

2. Elevator door operating mechanism, com prising, in combination, an actuating lever pivoted on the elevator cab and operatively linked atits lower end to said door, a pair of spaced pulleyshaving substantially parallel horizontal axes and. mounted on said cab one near each end. of the path of the other end of the lever, one of said prlleys being mounted for translatory movement laterally of the axis thereof, means urging said translatable pulley away from the other of said. pulleys, a p of flexible belting engaged in said pulleys, means for securing the upper end of said lever to the lower run of said belting such that said lever deflects the lower run of the belting toward the upper run in amounts that increase 7 toward the mid-position of the'lever, and a reversible motor for rotating one of said pulleys.

3. Elevator door operating mechanism, comprising, in combination, an actuating lever pivoted on the elevator cab and operatively linked at its lower end to said door, a pair of spaced pulleys having substantially parallel axes and mounted on said cab, one of said pulleys being mounted for translatory movement laterally of the axis thereof, means urging said translatable pulley away from the other of said pulleys, a loop of flexible belting engaged in said pulleys, means for securing the upper end of said lever to the lower run of said belting with the upper end of said lever and the point of connection of said belt thereto extending upwardly into the space between said pulleys and a reversible motor for rotating one of said pulleys.

4. Elevator door operating mechanism, comprising, in combination, an actuating lever pivoted on the elevator cab and operatively linked at its lower end to said door, a pair of spaced pulleys having substantially parallel horizontal axes and mounted on said cab, one of said pulleys being mounted for translatory movement laterally of the axis thereof, means urging said translatable pulley away from the other of said pulleys, a loop of flexible belting engaged in said pulleys, means for securing the upper end of said lever to the lower run of said belting with the upper end of said lever and the point of connection between said lever and said belt extending between said pulleys and above a horizontal plane tangential to the bottoms of said pulleys, whereby as the upper end of said lever travels with said belt between said pulleys, said translatable pulley is displaced to a lesser degree at each end of the travel of said lever than at the midpoint of the travel thereof and a reversible motor for rotating one of said pulleys.

5. Operator mechanism for elevator cab doors comprising, in combination, an actuating lever pivoted on the cab, linkage connecting the lower end of said lever to at least one of said doors, a pair of pulleys journaled on spaced parallel axes atop the cab, the first of said pulleys being translatable toward and away from the second of said pulleys, means urging the first of said pulleys away from the second of said pulleys, a loop of belting engaged in said pulleys for drivingly connecting said pulleys and limiting their movement apart, the upper end of said lever extending between said pulleys and movable in an are on a plane perpendicular to the axes of said pulleys, the lowermost points on such are lying not below a plane tangential to and beneath both of said pulleys, a clamp mounted on the upper end of said lever for connecting said lever to the lower run of said belting and a reversible motor drivingly connected to at least one of said pulleys.

6. High speed elevator car door operating mechanism comprising, in combination, a pair of pulleys having spaced, parallel, horizontal axes, a reversible motor drivingly connected to at least one of said pulleys, a loop of belting engaged in said pulleys, the first of said pulleys being mounted for translatory movement toward and away from the second of said pulleys, resilient means for urging the first pulley away from the second, a door actuating lever pivotally mounted on the car with one end operatively linked to said door and the other end extending into the space between said pulleys, said lever lying in a plane perpendicular to the axes of said pulleys, at least one fluid-containing control cylinder mounted adjacent the end of said lever and having a plunger, and a yoke pivotally connected to the rod of said plunger and rigidly connected to said lever and to the lower run of said belting between said pulleys.

7. In an elevator door operating mechanism for a sliding door of an elevator cab, in combination, an actuating lever pivoted on the elevator cab and having an end operatively linked to the door, a pair of spaced pulleys having substantially parallel axes and mounted on the cab one near each end of the path of the other end of said lever, a loop of flexible belting engaged in said pulleys, resilient means for maintaining said belting under tension, means for connecting the end of said lever to said flexible belting, said pulleys being located such that said lever deflects the connected run of the flexible belting in amounts that decrease from a maximum as the lever moves from the middle toward either end of its range of travel, and reversible means for driving one of said pulleys.

8. In an elevator door operating mechanism for a sliding door of an elevator cab, in combination, an actuating lever pivotally mounted on the cab and having an end operatively linked to the door, a flexible belt one run of which tends to extend along a chord of the path of the other end of the lever, a yoke on the end of the lever. said belt being attached to said yoke and deflected by said yoke toward the other run of the belt, means to keep tension in the belt, whereby said lever is urged toward the nearer one of the ends of its range of travel, a pair of hydraulic shock absorbers each including a cylinder and piston, said cylinders being pivotally connected to said cab and said pistons being connected to said yoke, and throttling means in said pistons and cylinders adapted to throttle the flow of hydraulic fluid and thereby increase the resistance of said shock absorbers to movement of said yoke as the lever approaches an end of its range of travel.

9. A door operating mechanism according to claim 8 in which the throttling means comprises a tapered pin fixed in said cylinder and adapted to enter and close an orifice in the piston as the piston approaches an end of its travel.

JOSEPH H. BORDEN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 700,404 Braden et al. May 20, 1902 1,486,278 Brady Mar. 11, 1924 1,572,218 Meyer Feb. 9, 1926 1,632,237 Lemon June 14, 1927 1,829,513 French Oct. 27, 1931 1,992,099 Smith Feb. 19, 1935 2,040,934 Gillen May 19, 1936 2,121,906 Dunn June 28, 1938 2,255,769 Gallagher et al Sept. 16, 1941 2,334,981 Ackley Nov. 23, 1943 

